PMD Products Portable Jewelry Ultrasonic Cleaner Battery Powered Great for Travel Cleans Glasses, Lenses, Dentures Battery powered great for travel and vacations Ultrasonic action, has lid, front on off switch Auto timer, LED power status light, uses 4-AA batteries 2/3 Cup capacity with removeable wash tray Great for jewelry, glasses, optics, dentures: Not suitable for use with fragile stones (e.g. pearls, opals, amber, emeralds, etc.).